Vibrating patient support apparatus with a spring loaded percussion device

ABSTRACT

A vibrating patient support apparatus has a spring loaded percussion device preferably for treatment of pulmonary problems of a patient. Preferably, the percussion device is part of a bed mattress and is located beneath an upper cushioning member of the mattress for patient comfort. The percussion device preferably has a resilient pad in contact with the cushioning member, a rigid member disposed below the pad, a plurality of springs engaged between the pad and rigid member, a cam in biased contact with the rigid member by the springs and an electric motor for rotating the cam.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. provisional patent application Ser. No. 60/677,732, filed May 4, 2005, the advantages and disclosure of this application is hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates generally to a patient support apparatus and more particularly to a spring loaded percussion device of a vibrating patient support apparatus.

BACKGROUND OF THE INVENTION

Patient support systems are well known in the art for providing therapy to a patient. A typical patient support apparatus comprises a mattress having a plurality of air bladders for supporting the patient against the bias of gravitational forces, a percussion device that alternates inflation and deflation of air bladders to provide percussion and vibration therapy to the patient, and a rotation device, usually positioned beneath the mattress, to rotate the patient from side to side. Percussion, vibration, and rotation therapy assist in reducing pulmonary problems and bed sores, respectively.

One example of a rotation device in a mattress is shown in U.S. Pat. No. 5,611,096 to Bartlett et al. and incorporated herein by reference in its entirety. The rotation device of Bartlett et al. has two selectively inflatable and deflatable air bladders lying longitudinally beneath the mattress to provide rotation therapy to the patient for reducing bed sores. A controller including an operator input panel and display is used to control the rotation device. The input panel includes a plurality of raised buttons for advancing through and adjusting parameters associated with rotation functions.

An example of a percussion or vibrating device in a mattress is shown in U.S. Patent Application Publication No. 2004/0193078 A1, to Flick et al. and incorporated herein by reference in its entirety. The percussion device of Flick et al. discloses a vibrating pad having a plurality of bladders that fill and deflate with the flow of air or fluid at a prescribed frequency controlled by a controller causing the above mattress or mattress cushion to vibrate. This vibration therapy is capable of reducing pulmonary problems such as the accumulation of secretions in the lungs.

Unfortunately, in some applications air controlled percussion devices with inflating/deflating bladders is not practical because of manufacturing cost or the absence of pressurized air. Moreover, to treat pulmonary problems, a percussion device preferably creates a vibration with tightly controlled vibration frequencies at tightly controlled amplitudes. This control can be difficult to design into bladder devices utilizing air pressure transients alone.

SUMMARY OF THE INVENTION

A vibrating patient support apparatus has a spring loaded percussion device preferably for treatment of pulmonary problems of a patient. Preferably, the percussion device is part of a bed mattress and is located beneath an upper cushioning member of the mattress for patient comfort. The percussion device preferably has a resilient pad in contact with the cushioning member, a rigid member disposed below the pad, a plurality of springs engaged between the pad and rigid member, a cam in biased contact with the rigid member by the springs and an electric motor for rotating the cam.

Preferably, the came has a spiraling cam surface for sliding contact with the push rod and that spirals radially outward from a radially inner end to a radially outer end. Extending between the inner and outer ends is a fall face. The fall face faces in a circumferential direction opposite to the direction of rotation and substantially lies in an imaginary plane common to the rotation axis.

Objects, features and advantages of the present invention include a patient support apparatus that has a relatively lightweight and manageable mattress having numerous devices for therapeutic treatment including an electrically operated percussion device capable of tightly controlled vibration frequencies and amplitudes. Other advantages of the apparatus include a relatively simple and robust design that is inexpensive to manufacture, reduces wear and warranty costs and reduces energy consumption.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a perspective view of a patient support apparatus of the present invention positioned on a hospital bed frame;

FIG. 2 is a cross-sectional view of the patient support apparatus taken along the line 2-2 in FIG. 1;

FIG. 3 is a cross-sectional view of the patient support apparatus taken along the line 3-3 in FIG. 1;

FIG. 4 is a schematic view of a control system of the patient support apparatus;

FIG. 5 is a schematic view of an air flow system of the present invention;

FIG. 6 is an exploded perspective view of a spring loaded percussion device of the patient support apparatus;

FIG. 7 is a side view of a cam of the percussion device;

FIG. 8 is an enlarged partial cross section of a percussion mechanism of the percussion; and

FIG. 9 is a block diagram of a modification to the percussion device of the patient support apparatus.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, a vibrating patient support apparatus of the present invention is generally shown at 10.

Referring to FIG. 1, the patient support apparatus 10 of the present invention is shown in combination with a mobile hospital bed frame 12. As illustrated, the hospital bed frame 12 typically includes a plurality of side rails 14 that can be lowered for patient transfer and raised to confine a patient. The hospital bed frame 12 can also include a plurality of adjustable sections including an adjustable head section 16 that is pivotally adjustable relative to a main body section 18 of the bed frame 12 to allow the patient to sit up while eating or visiting with family.

Still referring to FIG. 1, the patient support apparatus 10 preferably comprises a generally self-contained mattress or pad assembly 20 having a patient support surface 22. The mattress 20 is referred to as being self-contained since a substantial portion of the working components of the mattress 20 that are used to carry out multiple functions, including a plurality of therapeutic functions, are enclosed by a cover 24 of the mattress 20. The cover 24 can be any conventional material including, but not limited to natural fibers, polymeric materials, or combinations thereof. The cover 24 is preferably a vapor permeable material to be used in conjunction with a low air loss mechanism 26 of the mattress 20 described below.

Referring to FIG. 4, a controller 72 of the patient support apparatus 10 controls operation of a main pump 50 preferably located externally of the mattress 20. The main pump 50 supplies a controlled amount of pressurized air to multiple systems or devices of the mattress 20 that are generally located internally to the cover 24 of the mattress 20. These systems include; a low air loss device 82 having a low air loss control system 56 and the low air loss mechanism or perforated tubing 26, a firmness setting device 84 having a main valve system 58 and a main air bladder 36 (see FIG. 3), and a rotation device 88 having a rotation control system 62 and a rotation mechanism 40. The rotation mechanism 40 is preferably two air bladders 42 located beneath the percussion mechanism 38. The main air bladder 36, a spring loaded percussion mechanism 38, and rotation mechanism 40 are supported within the cover 24 of the mattress 20 by a base cushion 44 positioned within a perimeter of the frame 34. The base cushion 44 can be rigid or flexible and comprise an air bladder, or simply be constructed of conventional bedding materials such as foam, and the like.

Preferably, a pendant 28 of the controller 72 is supported by a tower 30 coupled electrically to the mattress 20 and preferably supported structurally by the bed frame 12. The pendant 28 includes user interface 32 of the patient support apparatus 10 used to operate at least a portion of the functions of the mattress 20. The user interface 32 is preferably of a touch-screen display type that is well known to those skilled in the art for operator input, as well as output, based upon the particular software used to configure the user interface or touch-screen display 32. Here, the touch-screen display 32 has input and output capabilities. These features are shown in application Ser. No. 11/260,452, filed Oct. 27, 2005, hereby incorporated by reference.

Referring to FIGS. 2-4, the mattress 20 has a generally peripheral frame 34 of a conventional bedding frame material. Such material can include, but is not limited to foam, polymeric materials, metal, gels, or combinations thereof. Generally disposed internally to the cover 24 of the mattress 20 is the main air bladder 36 of the firmness setting device 84, which is positioned within the perimeter of the frame 34 and immediately below an upper portion of the cover 24. The main air bladder 36 acts as the primary support for the patient and with a controlled flow of air into and out of the bladder 36 can be useful in controlling the temperature of the bedding material exposed to the patient.

The percussion-vibration mechanism 38 of the spring loaded percussion device 86 is positioned below the main air bladder 36, hereinafter referred to as the percussion mechanism 38. The percussion mechanism 38 provides both percussion and vibration therapy to the patient. The particular therapy being employed is dependent on the frequency or the number of beats per second generated by the percussion mechanism 38. For example, and not to be limited to these examples, the percussion therapy usually employs 1-7 beats per second (i.e. 1-7 hertz) and the vibration therapy employs 7 to 25 beats per second (i.e. 7-25 hertz). The percussion mechanism 38 employs a plurality of compression springs 130 and a rotating cam 104 to impart the percussion motion.

Preferably, a rotation mechanism 40 of the rotation device 88 for rotation therapy is positioned generally below the percussion mechanism 38. The rotation mechanism 40 provides rotation therapy to the patient by rotating the patient from side to side. Along with percussion and percussion-vibration therapy, rotation therapy assists in reducing bed sores and pulmonary problems of the patient. The rotation mechanism 40 is preferably a pair of longitudinally positioned rotation bladders 42, shown in FIG. 3 and described in the '078 publication to Flick et al. The rotation bladders 42 are independently inflated and deflated to raise one side of the patient, lower the patient, and then raise the other side of the patient such that the patient experiences a side-to-side rotation that shifts pressures between the patient and the bladder 36 of the firmness setting device 84 of the mattress 20.

Referring to FIGS. 3 and 4, the low air loss mechanism 26 of the mattress 20 used in conjunction with the encapsulating yet permeable cover 24 is preferably positioned inward of the cover 24. In operation, air is pumped from the low air loss mechanism 26 through the permeable cover 24 to reduce the temperature below the patient support surface 22 and decrease the chance of skin maceration that lowers the risk of bed sores. Preferably, the main pump 50 delivers pressurized air to the perforated tubing of the mechanism 26 disposed within the frame 34 and under the cover 24. The tubing is external to or spaced from the main air bladder 36, the percussion mechanism 38, and the rotation mechanism 40.

Referring specifically to FIG. 2, a first control unit 46 of a main control system 70 in the form of a rigid box and preferably not of the mattress 20 is shown adjacent to a foot end 48 of the mattress 20. The first control unit 46 encloses the main pump 50 and a power circuit board 52 of a main control system 70 for operating the main pump 50 and transferring power to the rest of the mattress components generally located in a second control unit 54. As shown, the first control unit 46 fits neatly below the foot end 48 of the mattress 20, but is not incorporated within the cover 24 of the mattress 20. Of course, other configurations with the first control unit 46 inside the cover 24 are also possible. Such configurations are illustrated in the '078 publication to Flick et al. In a preferred embodiment, the main pump 50 is used to inflate the main air bladder 36, the rotation bladders 42, and to convey air to the perforated tube 26.

The second control unit 54 of the main control system 70 in the form of a rigid box is shown beneath the cover 24 of the mattress 20 within the perimeter of the frame 34 (see FIG. 2). The second control unit 54 encloses the low air loss control system 56 for controlling the low air loss mechanism 26, the main valve system 58 for inflating and deflating the main air bladder 36, the percussion control system 60 for controlling the percussion mechanism 38, the rotation control system 62 for controlling the rotation mechanism 40, and a main circuit board 64 in operative communication with these systems and the power circuit board 52 of the first control unit 46. The second control unit 54 also preferably encloses a processor 74 and memory 78 of the controller 72 for controlling operation of these systems 56, 58, 60, 62 and the main pump 50. These systems 56, 58, 60, 62 may comprise motors, solenoid valves, and/or motor-controlled valves, as disclosed in the '078 publication. It should be appreciated that each of these separate control systems 56, 58, 60, 62 may also represent portions of a larger system. Those skilled in the art will now recognize that the systems employed for controlling operation of the loss air loss mechanism 26, main air bladder 36, percussion mechanism 38, and rotation mechanism 40 may assume a variety of configurations.

Referring to FIG. 4, the main control system 70 of the patient support apparatus 10 is schematically illustrated. The main control system 70 includes the controller 72 which comprises the processor 74, the touch-screen display 32, a display driver 76 for driving the touch-screen display 32, the memory 78, and a communication interface 80. The controller 72, via communication interfaces 80, is also in operative communication with the low air loss control system 56, main valve system 58, percussion control system 60, rotation control system 62, and the main pump 50.

Referring to FIG. 5, an air flow schematic of the patient support apparatus 10 is shown. The air flow schematic generally shows the movement of air through conduits from an air source 94 (preferably outside air at atmospheric pressure) via the main pump 50 to the second control unit 54 and more specifically, to the low air loss control system 56, the main valve system 58, the percussion control system 60, and the rotation control system 62. Each of these systems 56, 58, 60, 62 preferably comprises valve controls for operating their respective mechanisms, i.e., the perforated tube 26, the main air bladder 36, the percussion bladders 39, and the rotation bladders 42. Such valve controls are described in more detail in the previously referenced '078 publication to Flick et al. herein incorporated by reference. It should be appreciated that each of the separate control systems 56, 58, 60, 62 may be portions of a larger valve system, or the control systems 56, 58, 60, 62 may represent direct connections between the main pump 50 and the respective perforated tube 26 or bladders 36, 39, 42.

With further regards to the percussion device 86 and more specific to the present invention, FIGS. 6-8 illustrate the spring loaded percussion device 86 generally having an electric motor 100 having a stator that rotates about a substantially horizontal axis 102 and connected concentrically to a rotating cam 104. With respect to FIG. 7 and assuming the motor 100 rotates the cam 104 is a counter clockwise direction as designated by arrow 106, the cam 104 has a camming peripheral surface 108 that spirals in a radially outward direction as the surface 108 extends circumferentially in a clockwise direction from an inner end 110 to an outer end 112 of the surface 108. Extending radially between the ends 110, 112 of surface 108 is a fall face 114. Preferably, the fall face 114 does not extend, curve or slope circumferentially and instead faces in a clockwise direction. That is, the fall face 114 and the rotation axis 102 both substantially lie in the same imaginary plane.

Operatively engaging the percussion mechanism to the rotating cam 104 is a substantially vertical push rod 116 that reciprocates in and is supported by a sleeve 118 preferably attached to the frame 34 of the mattress 22. The push rod 116 has a lower end 120 that slides against the cam surface 108 and an upper end 122 engaged to a bottom surface 124 of a rigid member or plate 126. Extending upward from a top surface 128 of the rigid member 126 are a plurality of coiled compression springs 130. A lower end 132 of the springs 126 is engaged to the rigid member 126 and an upper end 134 is attached to the resilient pad 39. Preferably, the upper end 134 of each spring 130 is seated in an inverted cup or guard 136 secured to the pad 39 for wear protection of the pad 39.

In operation of the percussion device 86, the controller 72 actuates the electric motor 100 that rotates the cam 104, for example, in a counterclockwise direction 106. The lower end 120 rides along the cam surface 108 toward the outer end 112. During this time, the push rod 116 moves upward carrying the rigid member 126 with the rod and against the biasing forces of the springs 126, the resilient pad 39 and any patient weight placed upon the pad. Generally, the springs 126 will compress and the resilient pad 39 will generally lift upward. With continued rotation of the cam 104, the push rod 116 will ride circumferentially beyond the outer end 112 of cam surface 108 and with the biasing force of the compressed springs 130, the stretched or lifted pad 39 and any weight of the patient will fall radially inward along the fall face 114 and impact the inner distal end 110 of camming surface 108. This impact reverberates through the percussion mechanism 38 and contributes toward the vibration frequency and resultant amplitudes.

Referring to FIG. 9, a modification of the percussion device 86 is illustrated wherein the resilient pad 39 is actually a bladder inflated to a controlled pressure by the main pump 50 and similar to that described for the firmness setting device 84. Moreover, one skilled in the art would now realize that a single cam 104 can have multiple fall faces 114 facing in a common circumferential direction. Also, the electric motor can rotate a cam shaft (not shown) having multiple cams 104 each having a fall faces that are out of phase or circumferential alignment with one-another. Each cam 104 can operated respective multiple push rods 116 and associated multiple rigid members or plates 126 each having their own series of springs 130.

While the forms of the invention herein disclosed constitute presently preferred embodiments, many others are possible. It is not intended herein to mention all the possible equivalent forms or ramifications of the invention. It is understood that the terms used herein are merely descriptive rather than limiting, and that various changes may be made without departing from the spirit or scope of the invention. For instance, the term mattress as applied to mattress 20 is not meant to be limited to a patient's bed, but may apply to any pad assembly that supports all or any portion of a patient against the bias of gravitational forces and whether or not the patient is intended to actual sleep upon the mattress or pad assembly. In light of the present invention, one skilled in the art would now realize that the main bladder 36 of the firmness setting device 84 may be a passive cushioning member thus generally eliminating the firmness setting device 84 altogether. If such is the case, one skilled in the art would now know that the resilient pad 39 of the percussion mechanism 38 could be replaced with the cushioning member 36. 

1. A percussion device of a patient support apparatus for therapeutic treatment of pulmonary problems of a patient, the percussion device comprising: an electric motor; a cam connected operably to the electric motor; a rigid support member biased against the cam; a resilient pad spaced from the support member; and a spring engaged between the support member and the resilient pad.
 2. The percussion device set forth in claim 1 wherein the spring is a coiled spring having a upper first end connected to the resilient pad and an opposite lower end connected to the support member.
 3. The percussion device set forth in claim 2 further comprising a rotation axis of the motor wherein the cam is disposed concentrically to the rotation axis.
 4. The percussion device set forth in claim 3 further comprising: a cam surface of the cam facing radially outward; and a push rod in sliding contact with the cam surface at a first end and engaged to the support member at an opposite second end.
 5. The percussion device set forth in claim 4 wherein the cam surface has a radially inner first end and extends circumferentially in a spiral fashion to a radially outer second end.
 6. The percussion device set forth in claim 5 further comprising a fall face of the cam projecting radially outward from the inner first end to the outer second end.
 7. The percussion device set forth in claim 6 wherein the first end of the push rod is biased against the cam surface by the spring so that as the first end slides against the rotating cam surface the push rod moves radially outward against a biasing force of the spring until the first end of the push rod reaches the outer second end of the cam surface at which point the push rod falls radially inward and impacts the inner first end of the cam surface.
 8. The percussion device set forth in claim 6 wherein the fall face and the rotation axis both lie in a common imaginary plane.
 9. The percussion device set forth in claim 1 wherein the resilient pad is a pressure controlled bladder.
 10. The percussion device set forth in claim 1 wherein the spring is one of a plurality of springs.
 11. A patient support apparatus for providing therapeutic treatment to a patient, the patient support apparatus comprising a bed mattress having a cushioning member and a percussion device having a resilient pad located below the cushioning member, a spring disposed below and connected to the resilient pad, a cam engaged to the spring and an electric motor connected to the cam.
 12. The patient support apparatus set forth in claim 11 wherein the cushioning member is a main bladder inflated by a variable speed pump at a pressure controlled by a controller.
 13. The patient support apparatus set forth in claim 11 further comprising: the spring being one of a plurality of springs; and a rigid member of the percussion device having an upper surface engaged to the plurality of springs and a lower surface biased toward the cam by the plurality of springs.
 14. The patient support apparatus set forth in claim 13 further comprising a rotation device having two rotation bladders located below the rigid member of the percussion device, and wherein the two rotation bladders are independently inflated and deflated by a pump and controller.
 15. The patient support apparatus set forth in claim 13 further comprising: a cam surface of the cam facing radially outward; and a push rod in sliding contact with the cam surface at a first end and engaged to the rigid member at an opposite second end.
 16. The patient support apparatus set forth in claim 15 wherein the cam surface has a radially inner first end and extends circumferentially in a spiral fashion to a radially outer second end.
 17. The percussion device set forth in claim 16 further comprising a fall face of the cam projecting radially outward from the inner first end to the outer second end.
 18. The percussion device set forth in claim 17 wherein the fall face faces in a circumferential direction that is opposite to a direction of rotation of the cam. 